The present invention disclosed herein relates to electronic devices and, more particularly, semiconductor disk devices and related methods for randomly accessing data.
There is an ever-increasing demand for higher data storage capacities and densities in digital data storage units (devices). Among many kinds of information storage units, hard disk drives (HDDs) are widely used in digital processing systems because of their high recording data density, high data transmission rate, fast data read/write access, and low cost. A HDD includes a data storage disc, a head that reads and writes data on the disc, and a movable arm that positions the head relative to the disc. The disc functions as a nonvolatile storage medium for storing data, and can be formed from aluminum sheets coated with a magnetic substance. Those aluminum sheets can be referred to as a “platter”.
The HDD is a mechanical device that spins the disc and positions the head relative to the disk to carry out read and write operations. The basic structure and operational function of HDDs have been around since at least 1973 when the Winchester HDD (or non-removable disk drive) was introduced. For some digital data storage applications, the mechanical structure of the HDD has been supplemented and/or replaced by other kinds of data storage devices, such as nonvolatile random access memories (RAM). Some potential disadvantages of HDDs is that their mechanical operation makes their operation vulnerable to vibration, impact, air density, and mechanical wear/fatigue.
More recently, semiconductor disk devices, also called solid state disks (SSDs), have been introduced that employ flash memory architectures to store digital data. The commercial demand for SSDs has been rapidly increasing as they are increasingly used instead of HDDs in some applications. Compared to HDDs, SSDs do not yet provide a cost-effective alternative to HDDs for high data storage capacity requirements. However, with continuing advancements in SSD technologies, it is envisioned that SSDs will continue to replace HDDs for an increasing number of applications.